A new MVNO called Mint SIM has launched, boasting seriously low prices -- but there's a catch. The best prices comes when you buy a year's worth of data, which is the same as being locked into a contract.

Another day, another company trying to revolutionize the mobile carrier business. The competition among the top four carriers may be heating up, but they’re not the only options out there. A new mobile virtual network operator, or MVNO, recently popped up from Ultra Mobile.

The service is called Mint SIM, and it’s basically a no-contract service provider that offers fully featured talking, texting, and data plans at low prices.

Mint SIM is a little different than other recent carriers in that it really tries to lock you down — it offers low prices, but there’s a catch: you have to pay for longer periods of time than other services. So how cheap is it? Buy 12 months of service with unlimited talk and text, and 2GB of LTE data per month, and you’ll pay $21 per month. Not bad!

Of course, the price may be great, but the whole idea seems like a big step back. We’ve moved past the days when getting decent service meant having to sign your mobile life away. Still, the nice thing about Mint is that you don’t have to pay for a whole year — you can pay month-by-month, but you’ll pay extra. That same 2GB data deal, for example, costs $35 per month if you only pay for a month at a time.

Mint’s plans go all the way up to $42 per month if you pay for a year’s worth of 10GB per month data. Customers also don’t have to pay for a full year or only pay month-by-month — there are also three and six month plans available.

It’s certainly an interesting concept, but it’s hard to see Mint SIM really catching on. The company touts is service as “no contracts,” but paying for a year of service upfront is arguably the same thing as a contract. Sure, you can technically leave whenever you want, but you’ll lose money by doing so.